Draft regulator for furnaces



STUBNER 1,771,068

DRAFT REGULATOR FOR FURNACES Filed June 5, 1929 INVENTUR.

Patented July 22, 1930 WILLY s'rfiBNER, or EISENACH, GERMANY DRAFT REGULATOR FOR FURNACES Application filed June 5, 1929, Serial No.

The present invention relates to an improved draft regulator for furnaces, and has for its primary object automatically regulating admission of air to the chimney whereby undesirable increased draft due to sudden v gusts, changeability of the Wind, or changes of weather, are immediately equalized whereby a material economy of fuel is obtained.

It has already been proposed to automatically regulate admission of air to a chimney by means of a valve controlling an opening in the flue or chimney. In such an arrangement, the valve in the form of a disc controlling an opening in the. flue has been carried on the one end of a two armed lever the other end of which has carried a balance weight, but since the balance weight is always the same relative distance from the fulcrum, the weight moment decreases with the opening of the disc due to increased draft, so that it is impossible to obtain the required degree of sensitivity for efficient draft regulation.

The present invention comprises a draft regulator for furnaces in which a valve, car- 25 ried on the one end of a two armed lever, controlsan opening in the furnace flue and is counter balanced by aWeight so carried by an arm fixed on the other end of said lever as to alter the weight moment according to '30 the position of the valve, or in other words to increase the effective length of the weighted end of the lever as the other end thereof moves downwardly to increase the valve opening.

This invention will be now more particularly described making reference to the accompanying drawing, in which 2-- Fig. 1 is a view in side elevationpartly in sectionof an embodiment by Way of 'eX- ample of a furnace draft regulator con- StIlCtBd according to the present invention, an

F Fig. 2 is a view in section on line 22 of Throughout both views similar parts are marked with like letters of reference.

The apparatus consists substantially of a box or casing a, of rectangular, circular, or other suitable, shape in cross section, and is provided with an extension I), which, to-

368,623, and in Denmark June 15, 1928.

gether with the casing a, is fixed on or built into the chimney flue, the draft of which is to be controlled. This boX or casing a is divided into two chambers by means of a horizontally arranged partition 0 which is provided with an opening (1. Air enters the upper chamber through a perforated lid or cover 6 and passes through the opening 03 to the chimney shaft or fine through the extension 5. The opening d is controlled by a vertically and parallelly movable disc f taking a seating onthe under side of the opening d. This disc 7 is carried by a rod 9 which is pivoted byknife edges on the one arm k of a two armed lever. The two armed lever is pivoted at 2' by knife edges in a bracket or depending arm is carried by the lid or cover 6. To the other arm Z of the lever is fixed a depending arm on to which is attached a balance weight n. The arm mis adjustably fixed in any desired angular position with respect 'to the arm Z by means of a set screw m or in other convenient manner.

In order that the disc 7 may move in a vertical path with respect to its seatlng in the opening (Z, a link 0 is pivoted by means of knife edges both to the bracket or arm m and the rod 9. This link 0 is of the same length between its pivoting points as that between the pivoting point 27 and the pivot of the rod 9 on the arm and is so arranged as to be always parallel with said arm It.

In order that the position of the disc may be observed at any time, a dry draft-meter or indicator is fixed on the outside of the casing and is so connected to the disc as to render its varyingmovements visible outside the easing. A convenient form of indicator is that shown in which a spindle p, journalled in bearings p passes through the casing a. On the outer' end of this spindle p is fixed a pointer 10 adapted to move over a scale fixed on the outside of thecasing a. The inner end of the spindle p is furnished with a disc p', to the periphery of which is secured the one end of a flexible connection 1', the other end of which is fixed to the disc f, so that as the said disc rises or falls the spindle p and with it the pointer p is moved angularly.

In order to obtain ready access to the u per chamber and to allow for adjustment the angular position of the arm m, a door a is provided.

The apparatus functions in the following manner :-When the draft conditions are normal, the opening d is more or less closed by the disc! by the balance weight n. As soon as the raft in the fine or chimney is increased through an cause, such as a gust of wind, the increase draft causes the disc f to move downwardly and allows more secondary air to pass through the opening (I to equalize the increased induced draft. As the draft in the flue or chimney is increased the weight moment varies, because the effective length of the arm l of the lever is increased in proportion to its upward movement due to the downward movement of the disc f, as is clearly shown in dotted lines in Fig. 1. It will thus be seen that the disc f which by admission of fresh air shows an altered moment, so that with an increasing moment, the weight moment increases to the same amount so that both are balanced. The adjustabilityof the wei ht moment is eifected by varying the angle oi the arm m with respect to the lever Z which is readily accomplished by means of the screw m.

I declare that what I claim and desire to secure by Letters Patent is 1. A furnace draft regulator comprising a casin communicating with the chimney flue an through which the admission of air takes place, an air admission opening in said casing, a disc valve controlling said casing, a two armed lever pivoted within said casing, a depending arm carrying a balance weight, ad ustably fixed to the one arm of said lever, from the other arm of which the disc Valve is pivotally suspended, and means for ensuring the disc valve receiving a vertical motion, as set forth.

2. .A furnace draft regulator comprising a casing communicating with the chimney flue and through which the admission of air takes place, an air admission opening in said casing, a disc valve controlling said opening, a two armed lever pivoted within said casing, a depending arm capable of angular adjustment fixed to the one arm of said lever, a balance weight carried by said depending arm, a rod pivoted to the other arm of said lever and carrying the disc valve at its lower end, a link pivoted to the rod and a fixed point to cause the rod and disc valve to move with a vertical motion and a dry draft meter fixed on the outside of said casing and operated by mechanism connected to the disc valve, as set forth.

3, A furnace draft regulator comprising a casing communicating with the chimney flue, a horizontally arranged artition in said casing dividing it into two 0 ambers, a perforated lid covering the air inlet to the top oted between the rod and the depending support as to cause the disc to move in a vertical path, a dry draft-meter fixed on the outside or" the casing and connecting mechanism between said meter and the disc, as set forth.

WILLY STUBNER.

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